[WIP]: add v8.5.5 release notes #21195

qiancai · 2025-12-16T08:12:29Z

What is changed, added or deleted? (Required)

As in the title, this PR adds the release note doc for v8.5.5.

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This PR is translated from: [WIP]: add v8.5.5 release notes docs#22190
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ti-chi-bot · 2025-12-17T06:13:02Z

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releases/release-8.5.5.md

Co-authored-by: zhaoshangzi <zhaoshangzi@icloud.com> Co-authored-by: Frank945946 <108602632+Frank945946@users.noreply.github.com>

joechenrh

LGTM, for the ADD INDEX part.

ti-chi-bot · 2025-12-23T09:47:11Z

@joechenrh: adding LGTM is restricted to approvers and reviewers in OWNERS files.

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qiancai · 2025-12-24T06:47:59Z

releases/release-8.5.5.md

+
+    更多信息，请参考[用户文档](链接)。
+
+* 按时间点恢复 (Point-in-time recovery, PITR) 支持从压缩后的日志备份中恢复，以加快恢复速度 [#56522](https://github.com/pingcap/tidb/issues/56522) @[YuJuncen](https://github.com/YuJuncen) **tw@lilin90** <!--2001-->


这条的中文目前是从 v9.0.0 复制过来的之前的描述，麻烦请按照 https://github.com/pingcap/docs/pull/22190/files 里最新的英文进行调整 @lilin90

qiancai · 2025-12-24T06:48:14Z

releases/release-8.5.5.md

+
+    更多信息，请参考[用户文档](https://docs.pingcap.com/zh/tidb/v8.5/tikv-configuration-file#graceful-shutdown-timeout-从-v855-版本开始引入)。
+
+* 提升进行中的日志备份与快照恢复的兼容性 [#58685](https://github.com/pingcap/tidb/issues/58685) @[BornChanger](https://github.com/BornChanger) **tw@lilin90** <!--2000-->


这条的中文目前是从 v9.0.0 复制过来的之前的描述，麻烦请按照 https://github.com/pingcap/docs/pull/22190/files 里最新的英文进行调整 @lilin90

Co-authored-by: zhaoshangzi <zhaoshangzi@icloud.com>

releases/release-8.5.5.md

lcwangchao · 2025-12-25T02:43:24Z

releases/release-8.5.5.md

+
+* 提示索引下推到TiKV提升查询性能 [#62575](https://github.com/pingcap/tidb/issues/62575) @[lcwangchao](https://github.com/lcwangchao) **tw@qiancai** <!--1899-->
+
+    通过hint INDEX_LOOKUP_PUSHDOWN(t1_name, idx1_name [, idx2_name ...]) 提示优化器将指定索引查询下推到TiKV，减少远程调用的次数，经过测试数据对比显示性能可提升约20%左右，最优可提升到40%。本特性一般建议结合表 affinity 属性使用，即表属性 AFFINITY="table" 或者 分区表属性 AFFINITY="partition" 。


实际数据可能根据环境和负载不同有很大区别，这个数据目前是混合负载的结果，不光包含 pushdown

@zhaoshangzi PTAL

通过hint INDEX_LOOKUP_PUSHDOWN(t1_name, idx1_name [, idx2_name ...]) 提示优化器将指定索引查询下推到TiKV，减少远程调用的次数，性能在理论上有提升，但具体提升比例需要结合业务场景实际测试。本特性一般建议结合表 affinity 属性使用，即表属性 AFFINITY="table" 或者分区表属性 AFFINITY="partition" 。

qiancai · 2026-01-07T08:03:56Z

releases/release-8.5.5.md

+| -------- | -------- | -------- | -------- |
+| PD | [`schedule.max-affinity-merge-region-size`](https://docs.pingcap.com/zh/tidb/v8.5/pd-configuration-file#max-affinity-merge-region-size-从-v855-版本开始引入) | 新增 | 控制属于同一[亲和性](https://docs.pingcap.com/zh/tidb/v8.5/table-affinity)分组中相邻的小 Region 自动合并的阈值，默认值为 `256`，单位为 MiB。 |
+| PD  | [`schedule.affinity-schedule-limit`](https://docs.pingcap.com/zh/tidb/v8.5/pd-configuration-file#affinity-schedule-limit-从-v855-版本开始引入) | 新增 | 控制同时进行的[亲和性](https://docs.pingcap.com/zh/tidb/v8.5/table-affinity)调度任务数量，默认值为 `0`，表示亲和性调度默认关闭。 |
+| TiKV | [`performance.enable-async-batch-get`](https://docs.pingcap.com/zh/tidb/v8.5/tikv-configuration-file#enable-async-batch-get-从-v855-版本开始引入)  | 新增 | 控制 TiDB 是否使用异步方式执行 Batch Get 算子，默认值为 `true`。 |


Suggested change

| TiKV | [`performance.enable-async-batch-get`](https://docs.pingcap.com/zh/tidb/v8.5/tikv-configuration-file#enable-async-batch-get-从-v855-版本开始引入) | 新增 | 控制 TiDB 是否使用异步方式执行 Batch Get 算子，默认值为 `true`。 |

| TiDB | [`performance.enable-async-batch-get`](https://docs.pingcap.com/zh/tidb/v8.5/tidb-configuration-file#enable-async-batch-get-从-v855-版本开始引入) | 新增 | 控制 TiDB 是否使用异步方式执行 Batch Get 算子，默认值为 `true`。 |

releases/release-8.5.5.md

hfxsd · 2026-01-08T02:30:47Z

releases/release-8.5.5.md

+    - fix incorrect initialization for foreign key related fields when copying table info [#61668](https://github.com/pingcap/tidb/issues/61668) @[tangenta](https://github.com/tangenta)
+    - 修复多个 schema 变更时，内嵌于 DDL 的 Analyze 特性可能不会启用的问题 [#65040](https://github.com/pingcap/tidb/issues/65040) @[joechenrh](https://github.com/joechenrh)
+    - 修复取消 ADD INDEX 任务后，分布式执行框架 (Distributed eXecution Framework, DXF) 任务没有取消的问题 [#issue](https://github.com/pingcap/tidb/issues/64129) @[tangenta](https://github.com/tangenta)
+    - fix incorrect check to determing whether to load table info for tables contain foreign key [#60444](https://github.com/pingcap/tidb/issues/60444) @[JQWong7](https://github.com/JQWong7)


@joechenrh PTAL

hfxsd · 2026-01-08T02:31:54Z

releases/release-8.5.5.md

+    - 修复在升级时 TiDB 节点可能会卡住的问题 [#64539](https://github.com/pingcap/tidb/issues/64539) @[joechenrh](https://github.com/joechenrh)
+    - 修复当没有索引数据时，admin check 没有报错的问题 [#issue](https://github.com/pingcap/tidb/issues/63698) @[wjhuang2016](https://github.com/wjhuang2016)
+    - 修复执行 `MODIFY COLUMN` 修改排序规则时，数据索引不一致的问题 [#61668](https://github.com/pingcap/tidb/issues/61668) @[tangenta](https://github.com/tangenta)
+    - fix incorrect initialization for foreign key related fields when copying table info [#61668](https://github.com/pingcap/tidb/issues/61668) @[tangenta](https://github.com/tangenta)


@joechenrh PTAL

hfxsd · 2026-01-08T02:39:52Z

releases/release-8.5.5.md

+    - 修复缓存表在走 TiFlash 副本读取时可能出现的 goroutine 和内存泄漏问题 [#63329](https://github.com/pingcap/tidb/issues/63329) @[xzhangxian1008](https://github.com/xzhangxian1008)
+    - 修复执行 `ALTER TABLE child CHANGE COLUMN` 修改列后，外键 (Foreign Key) 没有更新的问题 [#59705](https://github.com/pingcap/tidb/issues/59705) @[fzzf678](https://github.com/fzzf678) <!--tw@hfxsd: the following 16 notes--> 
+    - 修复解码旧版本 TiDB 的 `RENAME TABLE` 任务 arg 时出现错误的问题 [#64413](https://github.com/pingcap/tidb/issues/64413) @[joechenrh](https://github.com/joechenrh)
+    - fix missing rebase auto increment not executed if BR restore failed [#64761](https://github.com/pingcap/tidb/issues/64761) @[joechenrh](https://github.com/joechenrh)


@joechenrh PTAL

releases/release-8.5.5.md

joechenrh · 2026-01-08T02:49:28Z

releases/release-8.5.5.md

+
+### SQL 功能
+
+* 支持在线修改分布式 `ADD INDEX` 任务的并发和吞吐 [#62120](https://github.com/pingcap/tidb/pull/62120) @[joechenrh](https://github.com/joechenrh) **tw@qiancai** <!--2326-->


Suggested change

* 支持在线修改分布式 `ADD INDEX` 任务的并发和吞吐 [#62120](https://github.com/pingcap/tidb/pull/62120) @[joechenrh](https://github.com/joechenrh) **tw@qiancai** 

* 支持在线修改分布式 `ADD INDEX` 任务的并发和吞吐 [#64947](https://github.com/pingcap/tidb/issues/64947) @[joechenrh](https://github.com/joechenrh) **tw@qiancai**

releases/release-8.5.5.md

Co-authored-by: Ruihao Chen <joechenrh@gmail.com>

releases/release-8.5.5.md

qiancai · 2026-01-08T09:05:33Z

releases/release-8.5.5.md

+
+    + TiCDC <!--tw@qiancai: 1 note-->
+
+        - 为创建 changefeed 增加更全面的检查 [#12253](https://github.com/pingcap/tiflow/issues/12253) @[wk989898](https://github.com/wk989898)


Suggested change

- 为创建 changefeed 增加更全面的检查 [#12253](https://github.com/pingcap/tiflow/issues/12253) @[wk989898](https://github.com/wk989898)

- 增强 Changefeed 的配置检查逻辑，在创建或更新 Changefeed 时，若 Dispatcher 配置引用的列不存在，将直接报错并拒绝操作，避免任务运行失败 [#12253](https://github.com/pingcap/tiflow/issues/12253) @[wk989898](https://github.com/wk989898)

releases/release-8.5.5.md

qiancai · 2026-01-08T09:33:30Z

releases/release-8.5.5.md

+        - 修复同步到存储类型下游时可能因为 writer close 操作失败而导致的数据丢失问题 [#12436](https://github.com/pingcap/tiflow/issues/12436) @[wk989898](https://github.com/wk989898)
+        - 修复同步 truncate partition 操作可能导致 changefeed 失败的问题 [#12430](https://github.com/pingcap/tiflow/issues/12430) @[wk989898](https://github.com/wk989898)
+        - 修复同步多表 DDL语句时产生的不正确的 DDL 执行顺序 [#12449](https://github.com/pingcap/tiflow/issues/12449) @[wlwilliamx](https://github.com/wlwilliamx)
+        - 升级 aws-sdk-go-v2 依赖以修复 glue schema 的注册问题[#12424](https://github.com/pingcap/tiflow/issues/12424) @[wk989898](https://github.com/wk989898)
+        - 修复引起 memory quota 无法正常释放的问题[#18169](https://github.com/tikv/tikv/issues/18169) @[asddongmen](https://github.com/asddongmen)
+        - 修复引起 memory quota 无法正常释放的问题[#18915](https://github.com/tikv/tikv/issues/18915) @[asddongmen](https://github.com/asddongmen)


Suggested change

- 修复同步到存储类型下游时可能因为 writer close 操作失败而导致的数据丢失问题 [#12436](https://github.com/pingcap/tiflow/issues/12436) @[wk989898](https://github.com/wk989898)

- 修复同步 truncate partition 操作可能导致 changefeed 失败的问题 [#12430](https://github.com/pingcap/tiflow/issues/12430) @[wk989898](https://github.com/wk989898)

- 修复同步多表 DDL语句时产生的不正确的 DDL 执行顺序 [#12449](https://github.com/pingcap/tiflow/issues/12449) @[wlwilliamx](https://github.com/wlwilliamx)

- 升级 aws-sdk-go-v2 依赖以修复 glue schema 的注册问题[#12424](https://github.com/pingcap/tiflow/issues/12424) @[wk989898](https://github.com/wk989898)

- 修复引起 memory quota 无法正常释放的问题[#18169](https://github.com/tikv/tikv/issues/18169) @[asddongmen](https://github.com/asddongmen)

- 修复引起 memory quota 无法正常释放的问题[#18915](https://github.com/tikv/tikv/issues/18915) @[asddongmen](https://github.com/asddongmen)

- 修复同步数据到对象存储（Storage Sink）时，可能因未正确捕获 Writer 关闭错误而导致数据丢失的问题 [#12436](https://github.com/pingcap/tiflow/issues/12436) @[wk989898](https://github.com/wk989898)

- 修复同步分区表的 `TRUNCATE` 操作可能导致 Changefeed 失败的问题 [#12430](https://github.com/pingcap/tiflow/issues/12430) @[wk989898](https://github.com/wk989898)

- 修复同步多表重命名 DDL 时，下游执行顺序可能不正确的问题 [#12449](https://github.com/pingcap/tiflow/issues/12449) @[wlwilliamx](https://github.com/wlwilliamx)

- 升级 `aws-sdk-go-v2` 依赖版本，以修复使用 Glue Schema Registry 时可能遇到的连接错误 [#12424](https://github.com/pingcap/tiflow/issues/12424) @[wk989898](https://github.com/wk989898)

- 修复 TiKV CDC 组件重启后可能无法正确释放内存配额，导致 Changefeed 任务卡住的问题 [#18169](https://github.com/tikv/tikv/issues/18169) @[asddongmen](https://github.com/asddongmen)

- 修复 TiKV CDC 在增量扫描任务堆积时，gRPC 连接可能因误判为空闲而被异常断开的问题 [#18915](https://github.com/tikv/tikv/issues/18915) @[asddongmen](https://github.com/asddongmen)

@hongyunyan PTAL

ti-chi-bot · 2026-01-08T10:06:05Z

@qiancai: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

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Add temp.md

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qiancai added do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. translation/from-docs This PR is translated from a PR in pingcap/docs. labels Dec 16, 2025

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Create release-8.5.5.md

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qiancai self-assigned this Dec 16, 2025

add feature description for #56522 and #58685

42a91b0

add pingcap#17221

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Frank945946 reviewed Dec 22, 2025

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zhaoshangzi reviewed Dec 23, 2025

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Add three features

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Co-authored-by: zhaoshangzi <zhaoshangzi@icloud.com> Co-authored-by: Frank945946 <108602632+Frank945946@users.noreply.github.com>

joechenrh approved these changes Dec 23, 2025

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add more features according to English PR

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qiancai commented Dec 24, 2025

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add improvements and bug fixes

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qiancai and others added 2 commits December 25, 2025 09:55

add two new features

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Co-authored-by: zhaoshangzi <zhaoshangzi@icloud.com>

adjust the feature order and add two features

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qiancai commented Dec 25, 2025

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